Listeriosis patients asked to list foods eaten over 30 days

Would you be able to list every single thing you have eaten in the past month?

That is what victims of South Africa’s massive listeriosis outbreak – the biggest on record globally – are being asked to do by the National Institute for Communicable Diseases in an attempt to pinpoint the source of infection.

The number of confirmed listeriosis cases is now 852‚ and 107 people have died‚ with the current death rate being a staggering 30%.

Of those confirmed cases‚ 42% were babies of less than a month old‚ with pregnant women being 20 times more likely to get listeriosis than other healthy adults.

Contracted by eating food containing the pathogen listeria‚ listeriosis is by far the most deadly of food-borne diseases‚ and given the scale of our mystery outbreak‚ it’s led to what one delegate termed “listeria hysteria”.

While patés‚ soft cheeses and guacamole have been found to be the source in listeriosis outbreaks in other countries‚ our outbreak is unlikely to be a high-end luxury food item‚ the NICD’s Dr Juno Thomas said at a listeriosis workshop hosted by the SA Association for Food Science (SAAFoST) and Technology in Johannesburg yesterday.

“So far our epidemiological investigation team has interviewed about 60 listeriosis victims to find out what they ate‚ day by day‚ during the month before they became symptomatic‚ in an attempt to identify patterns of consumption and indicate what we can eliminate‚” Thomas said.

“None had eaten smoked fish‚ for example.”

Food safety expert and SAAFoST president Lucia Anelich said given that a single‚ unique “homegrown” strain of listeriosis was identified in more than 90% of the confirmed cases‚ it was likely that the source was a single food product or range of products consumed by both rich and poor.

“Cold meats‚ for example‚ range from viennas and polony to more expensive slices of ham‚” she said.

As listeria is killed during the cooking process‚ the culprit is thought to be a ready-to-eat food – fruit or vegetables.